A South Korean news agency is reporting that North Korea has apparently failed in its attempt to test-fire a ballistic missile from a submarine in the Sea of Japan.

Yonhap quoted a South Korean official as saying North Korea fired the missile between 2:20 p.m. and 2:40 p.m. local time Saturday, but the launch was unsuccessful. He said debris from the missile was found on the sea's surface.

South Korea's Defense Ministry refused to confirm the report.

North Korean media reported last May that the country successfully test-fired a submarine-based ballistic missile, in what would be an indication of the country's advancing military technology.

The official KCNA news agency said North Korean leader Kim Jong Un attended the testing said the launch was "an eye-opening success."

North Korea is under U.N. sanctions banning it from developing or using ballistic missile technology.